Compressors are used in applications such as turbochargers, superchargers and the like. Such devices typically include a compressor wheel that includes an array of aerodynamically contoured impeller blades that are supported on a central section. The central section, such as a hub section, is mounted on a rotatable drive. In the case of a turbocharger, the rotatable shaft is driven by the turbine wheel. For turbochargers, the hub section generally includes a central axial bore into which the shaft extends and is fastened to the hub. Fastening can take any suitable form, such as the use of a threaded shaft and hub, a keyed hub or, alternately, a nose of the shaft may extend through the hub and be fastened thereto using a nut to tighten the hub against a shoulder or other diametrically enlarged structure rotatable with the shaft. The shaft rotatably drives the centrifugal compressor wheel in a direction such that the contoured blades draw in air axially and discharge that air radially outwardly at an elevated pressure level into a chamber of a compressor housing. The pressurized air is, then, supplied from the chamber to the air intake manifold of an internal combustion engine for admixture and combustion with fuel, all in a well-known manner.
Improvements in compressor technology have resulted in a variety of benefits including, but not limited to, increased compressor efficiencies, flow ranges and rapid transient response by careful design of the compressors, particularly the centrifugal compressor wheels. In order to provide increased performance, the use of polymeric centrifugal compressor wheels have been proposed. In certain applications and configurations, it is believed that polymeric compressor wheels can provide high strength and low rotational inertia components. In certain applications, polymeric compressor wheels can be more readily configured into desired vane and fin shape associated with the blades.
Polymeric compounds exhibit creep at compressor operating temperatures that can compromise their operational efficiency. It is desirable to provide a compressor wheel configuration that can provide the efficiencies of polymeric structures without issues of creep and distortion.